1. Field of the Invention
The present invention relates to a gyration tool, particularly a driving rotation tool used to screw or unscrew a workpiece worn out or damaged.
2. Description of the Related Art
A wrench as one tool to screw or unscrew a nut or a bolt head in regular work usually needs a socket, which is held in the wrench for occluding the nut (or the bolt head), and is turned to drive the socket as well as the nut or the bolt head for completion of screwing or unscrewing. In this regard, a relative slip is common in the socket in which the nut or the bolt head with some edges or corners worn out or damaged after long-term usage is held and leads to failure of screwing or unscrewing the nut or the bolt head. Accordingly, a technology as shown in FIG. 1 features a socket 90 with a coupling hole 91 surrounded by raised resisting bevels 92, each of which has a recessive slanted angle and is opposite to and resists a midpoint of every edge on a nut 100 (or a bolt head), for turning the nut 100 (or the bolt head). However, a force to completely screw or unscrew the nut 100 (or the bolt head) is insufficient and fails in driving the nut 100 (or the bolt head) in virtue of restrictive line contacts between the nut 100 (or the bolt head) and the socket 90.
To settle the above problem of a relative slip between the socket and the nut (or the bolt head), an alternative technology (R.O.C Patent No. M323375) as shown in FIG. 2 provides a non-slip socket on which a stable force can be applied forward and reversely: a socket 95 is provided with (a) a hexagon coupling hole 96 which is used to drive a workpiece head 100A (a nut or a bolt head) and (b) rectangular resisting parts 97 axially located at centers of at least three inner walls and contacting all peripheral surfaces of the workpiece head 100A vis-à-vis.
However, the above technology for a non-slip socket driving a nut or a bolt head and minimizing drawbacks such as slippage relative to the nut or the bolt head still has some problems, for instance, the socket 95 needs the rectangular resisting parts 97 axially located at centers of at least three inner walls in order to hold the workpiece head 100A (a nut or bolt head) inside the coupling hole 96 of the socket 95 for exact touches of all contact surfaces which complicate an operation and waste more time; the socket 95 is also taken as an unideal design because the workpiece head 100A with one side bulged or deformed is difficultly or hardly inserted into the socket 95. Furthermore, its deserved to be corrected that the prior art for a non-slip socket which depends on at least three contact surfaces for occlusion may lead to unstable (or shaken) gyration or separation of a workpiece with its workpiece head 100A deformed during application of force. Against this background, it has become a critical issue to correct and get over drawbacks in the prior socket by persons skilled in the industry.
Accordingly, the inventor having considered an imperfect structural design and other drawbacks of the prior art and attempted to optimize a socket with features such as convenient application, stable operation and no excessive waste of nuts or bolt heads has studied and developed the present invention of a driving rotation tool for serving the general public and promoting development of the industry.